These stoneware ceramics with thick green glazes are found throughout the Indonesian Archipelago. They were a form of barter currency. They simply functioned as a trade that was like money, and they had additional practical applications. The Indonesians stored pickled eggs, vegetables and other contents in these strong ceramics. The actual kiln site in Southern China where these wares were made has been active for two thousand years, since the Han Dynasty. It is the longest producing ceramic site on earth. Sometimes ceramics like these are called Exportware by experts because they were made with maritime trade in mind.